Australian news, and some related international items

Promoting nuclear wastes as fuel for space travel!

Nuclear waste to fuel Neptune mission THE AUSTRALIAN BY: JONATHAN LEAKE The Times September 30, 2012 BRITAIN’S burgeoning stockpile of nuclear waste may finally be put to good use – as fuel for Europe’s future missions to the solar system’s most distant and exotic planets such as Uranus and Neptune.

The European Space Agency (ESA) and Britain’s National Nuclear Laboratory (NNL) want to use radioactive isotopes harvested from the waste to make the nuclear batteries essential to power such space probes.

Nuclear batteries have been used by the American and Russian space
agencies since the 1960s, but Europe has not developed such
technologies until now. This has limited it to exploring only those
parts of the solar system that have enough sunlight to power solar
panels.

“The ESA wants the ability to explore the most distant and darkest
parts of the solar system,” said Jean-Pierre Lebreton, a senior
scientist with ESA for 32 years where he oversaw the Huygens mission
to Titan, Saturn’s largest moon……

Under the scheme the NNL, which operates the $A436 million Central
Laboratory facility at Sellafield, will exploit the 100-plus tons of
plutonium waste stored on the site. That plutonium has been in storage
for up to four decades and over that time some has radioactively
decayed, producing an isotope called americium-241 which is ideal for
nuclear power packs. The NNL has set up a trial production line to see
if this can be extracted from the plutonium.

Tim Tinsley of NNL said there were about two tons of americium in the
plutonium stored at Sellafield: “We estimate that we could build a
plant, produce 10kg of americium a year, and then decommission the
plant for ESA at a lifetime cost of a few hundred million euros.
Britain would gain investment and jobs and it would help us clean up
our plutonium stocks.”

ESA and NNL aim to create a prototype power pack within the next few
years, but the first nuclear battery is unlikely to fly until the
mid-2020s because of safety problems, especially the risk of a launch
going explosively wrong. The extra time will be used to develop a
containment system that can withstand explosions or the burning heat
of a forced re-entry.
NASA’s own Curiosity rover, now exploring Mars, is also
nuclear-powered and there were fears that if its launch last year had
gone wrong it could have released its 5kg of plutonium as deadly
radioactive dust. In 1978 there was just such an accident when Cosmos
954, a Soviet satellite, fell to Earth over Canada, scattering
radioactive waste across a 50,000 square mile area.

Richard Ambrosi, a reader in physics at Leicester University, which is
working on the same project, said safety was vital. “We are looking at
multiple layers of containment. A typical power pack might have 10kg
of americium in pellets. Around that you would have multiple layers to
contain the radioisotope. And around that you would have a heat
shield.”

For ESA the option of using nuclear power packs could be a boon. At
the moment it is building the ExoMars rover, for launch in 2018, but
this will be solar-powered, with its panels vulnerable to dust and
other problems.

ESA is also due to launch the Jupiter Icy Moons Explorer (Juice) in
2022, which will explore Callisto, Europa and Ganymede, which are
thought to have liquid oceans under their frozen exteriors and so
could harbour life. Juice will be solar-powered, but its distance from
the sun means it will need solar panels of 860 square feet.